[time-nuts] time-nuts Digest, Vol 112, Issue 65

[Joseph Gwinn]

On Thu, 21 Nov 2013 09:40:44 -0500, time-nuts-request at febo.com wrote:
time-nuts Digest, Vol 112, Issue 65
> 
> Message: 8
> Date: Thu, 21 Nov 2013 06:40:14 -0800
> From: "Tom Van Baak" <tvb at LeapSecond.com>
> To: "Discussion of precise time and frequency measurement"
> 	<time-nuts at febo.com>
> Subject: Re: [time-nuts] Strange 100ns jumps on Motorola M12+T
> Message-ID: <81E050E96BC946FEAC01752F44CE988D at pc52>
> Content-Type: text/plain;	charset="iso-8859-1"
> 
>> The 100ns is exactly one cycle at 10 MHz.  GPS receivers use this, or 
>> something very close, as an internal clock.
> 
> Joe,
> 
> The vintage Oncore VP used a 9.54 MHz clock (which is why its 
> sawtooth is about +/- 52 ns).
> 
> Stephan is using the newer M12+T (~40 MHz clock, which is why its 
> sawtooth is about +/- 13 ns).
> 
> A 100.0 ns offset is more likely something to do with 10.00 MHz, 
> which is why I suspect connections and settings of the 53131A counter.
> 
> /tvb

Could be.  I don't completely visualize the setup, but given the noise 
shown in the plot, could we reliably tell 100ns from 105ns?

Joe Gwinn